Java Dump Stack Programmatically

package com.j256;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

/**
 * Code which writes a stack dump for all threads to a file.
 */
public class DumpStack {

    // directory where the stack files are written
    private static final String STACK_DUMP_DIR = "/var/tmp";

    // here for testing
    public static void main(String[] args) throws Exception {
        dumpStacks();
    }

    public static void dumpStacks() throws IOException {
        ThreadMXBean mxBean = ManagementFactory.getThreadMXBean();
        ThreadInfo[] threadInfos = mxBean.getThreadInfo(mxBean.getAllThreadIds(), 0);
        Map<Long, ThreadInfo> threadInfoMap = new HashMap<Long, ThreadInfo>();
        for (ThreadInfo threadInfo : threadInfos) {
            threadInfoMap.put(threadInfo.getThreadId(), threadInfo);
        }

        // choose our dump-file
        File dumpFile = new File(STACK_DUMP_DIR, "stacks." + System.currentTimeMillis());
        Writer writer = new BufferedWriter(new FileWriter(dumpFile));
        try {
            dumpTraces(mxBean, threadInfoMap, writer);
        } finally {
            writer.close();
        }
    }

    private static void dumpTraces(ThreadMXBean mxBean, Map<Long, ThreadInfo> threadInfoMap, Writer writer)
            throws IOException {
        Map<Thread, StackTraceElement[]> stacks = Thread.getAllStackTraces();
        writer.write("Dump of " + stacks.size() + " thread at "
                + new SimpleDateFormat("yyyy/MM/dd HH:mm:ss z").format(new Date(System.currentTimeMillis())) + "\n\n");
        for (Map.Entry<Thread, StackTraceElement[]> entry : stacks.entrySet()) {
            Thread thread = entry.getKey();
            writer.write("\"" + thread.getName() + "\" prio=" + thread.getPriority() + " tid=" + thread.getId() + " "
                    + thread.getState() + " " + (thread.isDaemon() ? "deamon" : "worker") + "\n");
            ThreadInfo threadInfo = threadInfoMap.get(thread.getId());
            if (threadInfo != null) {
                writer.write("    native=" + threadInfo.isInNative() + ", suspended=" + threadInfo.isSuspended()
                        + ", block=" + threadInfo.getBlockedCount() + ", wait=" + threadInfo.getWaitedCount() + "\n");
                writer.write("    lock=" + threadInfo.getLockName() + " owned by " + threadInfo.getLockOwnerName()
                        + " (" + threadInfo.getLockOwnerId() + "), cpu="
                        + (mxBean.getThreadCpuTime(threadInfo.getThreadId()) / 1000000L) + ", user="
                        + (mxBean.getThreadUserTime(threadInfo.getThreadId()) / 1000000L) + "\n");
            }
            for (StackTraceElement element : entry.getValue()) {
                writer.write("        ");
                writer.write(element.toString());
                writer.write("\n");
            }
            writer.write("\n");
        }
    }
}